Optical, thermal, and mechanical properties of aliphatic polydithiourethane (PDTU) films synthesized with diisothiocyanates and dithiols having methylene chains of different carbon numbers as monomers were evaluated, and the effect of methylene chain length on the properties of the resulting polymers was investigated. Furthermore, we compared the physical properties of network PDTU films synthesized with trifunctional isothiocyanates or trifunctional thiols as crosslinkers with those of films molded from chain polymers, and investigated their chemical recycling behavior.

Resole is obtained from phenol and formaldehyde under basic conditions and is cured by heating. We try to prepare wight-saving cured resole resins by using cyclic phenolic compounds as curing agents. Novel resole resins (R-CR(10)s) were prepared by curing resole and calix[4]resorcinarene (CR(10)), which is a cyclic tetramer consisting of resorcinol backbone and undecanal. The resulting R-CR(10)s showed excellent heat resistance and light-weight properties compared to the resole resin without curing agents. Furthermore, P-CR(10), in which CR(10) was polymerized by methylene crosslinking, was prepared and used as the curing agent for the resole resins. P-CR(10) also worked for a curing agent for resole and added light-weight properties to the cured resins. It was found that the light-weight properties of cured resole resins could be achieved while maintaining the heat resistance by using cyclic phenolic compounds as curing agents.

Amidoamine oxide surfactants (AAOs), in which multiple amide groups are introduced as hydrogen bonding sites into long-chain alkylamine oxides, which are general-purpose surfactants also used in kitchen detergents, form polymer-like aggregates in water or electrolyte solutions and act as low-molecular-weight gelators. AAO thickens and gels water at concentrations as low as 3%. Its gelation temperature is strongly influenced by its chemical structure. The authors investigated how the number of amide groups and the methylene chain length of each moiety affect the aggregate structure using AAOs with systematically varied chemical structures, and found the conditions that control the aggregate structure (rod-like or ribbon-like structure). It was also found that the viscoelasticity of a gel-like aqueous solution strongly depends on the aggregate structure. That is, the viscoelasticity of aqueous gel-like solutions was successfully controlled by appropriately adjusting the chemical structure of AAOs.

Novel polymerizable liquid crystals (PLC) molecules for curable resin to use in 5G, beyond 5G, and A.I. electronic devices have developed. Core structure and other parts have re-designed from PLC molecules for optical use such as a phase difference film. Finally, we succeed in obtaining the PLC monomers which have both low dielectric properties and high thermal conductive properties. In this synopsis, we explain the design methods of PLC and the experimental results.

Epoxy resins are essential materials in electronics, but chlorine compounds from epichlorohydrin in their manufacture cause metal corrosion and defects. Traditional cleaning methods are limited, so we developed a new two-step manufacturing process using allylation and epoxidation to create halogen-free epoxy resins. Utilizing hydrogen peroxide as an oxidant, we achieve high-yield of environmentally friendly epoxy compounds. This paper discusses the industrial value, molecular design, characteristics, and benefits of four high-performance epoxy resins (bifunctional aliphatic, multifunctional aliphatic, bifunctional aromatic, and multifunctional aromatic). These resins are low in chlorine, high in purity, and exhibit excellent performance, particularly in electronic applications. The oxidation method promises to develop new functional epoxy resins, offering higher performance materials in the future.